The present invention relates to a novel insole for footwear especially useful for relieving heel pain.
Pain on the bottom or side borders of the heel of the foot (in the center bottom, lower sides, or front of the heel) is known as plantar heel pain or bottom-of-heel pain. Such pain can be caused by various diseases such as arthritis, gout or diabetes or by several mechanically induced causes. The mechanical causes include such factors as plantar fasciitis, heel spurs, heel bruises, thinning or loss of fat from the fat pad on the bottom of the heel (the body's own natural heel cushion), strains, bursitis, nerve entrapment, or stress from high and rigid arches. Plantar faciitis is an inflammation of the plantar fascia (a fibrous sheath that encapsulates the ligament that runs along the bottom of the foot) near the point where it attaches to the front surface of the calcaneous or heel bone. The inflammation is believed to be caused by microtears of the plantar fascia caused by excessively stretching and/or twisting of the plantar fascia. Heel spurs are calcium deposits which grow on the front of the calcaneus and stick out into the plantar fascia and irritate this sensitive heel tissue. Further, arch pain often accompanies or is associated with bottom-of-heel pain. Such arch pain can arise from a sufferer's attempt to alleviate or minimize the bottom-of-heel pain by an abnormal walking gait. A search of the literature over the past 20 years uncovered very few patents which even addressed the subject of plantar heel pain. Generally, the theraputic approach has required the use of rigid prescription (i.e. custom-fitted) orthotic with a thin topcover to control foot motion. Accordingly, research was conducted to develop an insole which would relieve planter heel pain from the various mechanical causes or factors and could be mass-produced in a select number of sizes to fit the general population.